You can't really assume that every driver can't see you. Life doesn't work that way. If we assume we are invisible we would stop at every intersection when there is oncoming traffic that might decide to turn. We wouldn't ride slower than traffic because someone might right hook us. We would never take the lane. We have to ride defensively and be as visible as we can be, but nevertheless we do make some assumptions about being seen. As a practical matter, we have to.
I never go out anymore without high visibility clothing and flashing lights but I know it doesn't make me safe. Maybe it makes me safer though.
Trek Madone 4.7 WSD
Cannondale Quick4
1969 Schwinn Collegiate, original owner
Terry Classic
Richard Feynman: “The first principle is that you must not fool yourself and you are the easiest person to fool.”